M1148 Paper 2 Publication Files

Author

David Schneck

Published

November 6, 2024

Maternal Biomarker Information Across Visits

Characteristic 14_16w, N = 1,2951 19_21w, N = 1,3011 32_34w, N = 6501
Ferritin_ugL 55 (34, 81) 35 (21, 59) 15 (9, 24)
Ferritin_less15 58 (4.5%) 171 (13%) 332 (51%)
Ferritin_less30 269 (21%) 549 (42%) 543 (84%)
Ferritin_less12 33 (2.5%) 107 (8.2%) 258 (40%)
sTFR_mgL 3.36 (2.98, 3.77) 3.62 (3.24, 4.10) 4.73 (4.03, 5.68)
sTFR_Deficiency 88 (6.8%) 201 (15%) 398 (61%)
BIS_mgkgBW 8.6 (6.7, 10.1) 6.8 (4.7, 8.6) 2.6 (0.5, 4.7)
BIS_Deficiency 7 (0.5%) 17 (1.3%) 130 (20%)
CRP_mgL 2.8 (1.2, 6.3) 2.8 (1.2, 6.4) 2.6 (1.2, 5.7)
CRP_elevated 420 (32%) 415 (32%) 193 (30%)
CRPAGP_elevated 421 (33%) 415 (32%) 194 (30%)
CRP_greater5 420 (32%) 415 (32%) 193 (30%)
CRP_greater10 74 (5.7%) 84 (6.5%) 29 (4.5%)
AGP_gL 0.56 (0.49, 0.65) 0.52 (0.45, 0.61) 0.51 (0.45, 0.60)
AGP_elevated 12 (0.9%) 2 (0.2%) 2 (0.3%)
1 Median (IQR); n (%)

Cord Biomarker information

Characteristic N = 2601
Ferritin_ugL_cord 171: (63, 112, 225, 282)
sTFR_mgL_cord 7.64: (4.93, 6.44, 8.87, 12.88)
BIS_mgkgBW_cord 9.57: (5.39, 8.02, 11.04, 12.28)
CRP_mgL_cord 0.00: (0.00, 0.00, 0.20, 0.47)
AGP_gL_cord 0.20: (0.11, 0.16, 0.26, 0.37)
1 Median: (5%, 25%, 75%, 95%)
Characteristic N = 2601
CRP > 5 7 (2.7%)
CRP > 10 2 (0.8%)
AGP > 1
    No 260 (100%)
sTFR > 4.4 257 (99%)
TBI < 0 3 (1.2%)
1 n (%)

Demographics of All mothers vs Mothers with cord information

Firs table represents mothers with at least one visit information on biomarkers (out of 15,20,33 weeks). The second is the mothers with cord biomarker data.

The third table here represents the p values for bootstrap tests. These tests illustrate if our true sample of mothers with cord biomarkers are different from the overall population of mothers we have in this study.

Our mothers with cord biomarkers have babies with larger birthweights and lower rates of SGA.

Characteristic N = 1,3161
Ethnicity_White 1,282 (98%)
    Unknown 2
CountryofBirth_Ireland 1,051 (80%)
Relationship_Stable 1,236 (94%)
IncomeHousehold_less21k 111 (8.8%)
    Unknown 52
University_education 933 (71%)
Maternal_Age_Delivery 31.0 (28.0, 33.0)
Smoker_1st_trim 294 (22%)
Maternal_Obesity_14_16w 164 (12%)
    Unknown 1
Delivery_Mode_CS 368 (28%)
    Unknown 10
Sex 579 (44%)
    Unknown 7
Infant_GAw 40.00 (39.00, 41.00)
    Unknown 6
Preterm 64 (4.9%)
    Unknown 6
SGA 125 (9.5%)
    Unknown 1
Birthweight 3,480 (3,160, 3,795)
    Unknown 9
1 n (%); Median (IQR)
Characteristic N = 2601
Ethnicity_White 250 (96%)
CountryofBirth_Ireland 205 (79%)
Relationship_Stable 244 (94%)
IncomeHousehold_less21k 20 (7.8%)
    Unknown 5
University_education 195 (75%)
Maternal_Age_Delivery 32.0 (29.0, 34.0)
Smoker_1st_trim 50 (19%)
Maternal_Obesity_14_16w 39 (15%)
Delivery_Mode_CS 66 (25%)
    Unknown 1
Sex 104 (40%)
    Unknown 1
Infant_GAw 40.00 (39.00, 41.00)
    Unknown 1
Preterm 7 (2.7%)
    Unknown 1
SGA 15 (5.8%)
    Unknown 1
Birthweight 3,550 (3,290, 3,855)
    Unknown 1
1 n (%); Median (IQR)
Variable Exact p value
White 0.148
Country of Birth = Ireland 0.7
Stable Relationship 0.914
HH Income < 21k 0.581
University Education 0.153
Maternal Age @ Delivery 0.074
Smoker 0.222
Obesity 0.247
C-Section 0.343
Sex 0.208
Infant GA (weeks) 1
Preterm 0.097
SGA 0.048
Birthweight 0.006

Cord Ferritin Density Plots

Cord Biomarker Scatterplots

Quick look at Maternal Ferritin for cord Ferritin < 76

Birth Outcomes split by Maternal Ferritin Status

In order: Ferritin < 15µg/L @ 15weeks, 20 weeks, 33 weeks

Characteristic ID, N = 631 Non-ID, N = 1,2741 p-value2
C-section Delivery 14 (23%) 365 (29%) 0.3
    Unknown 1 10
Infant_GAw 40.00 (39.00, 40.75) 40.00 (39.00, 41.00) 0.4
    Unknown 1 5
Preterm 3 (4.8%) 60 (4.7%) >0.9
    Unknown 1 5
Apgar Score at 1min 9.00 (9.00, 9.00) 9.00 (9.00, 9.00) 0.2
    Unknown 1 18
Apgar Score at 5min 10.00 (9.00, 10.00) 10.00 (9.00, 10.00) 0.8
    Unknown 1 18
Birthweight 3,510 (3,250, 3,690) 3,480 (3,160, 3,800) >0.9
    Unknown 1 8
Birthweight Centile 46 (27, 64) 44 (22, 70) 0.8
    Unknown 1 9
LBW 6 (9.7%) 54 (4.3%) 0.056
    Unknown 1 8
Small for Gestational Age 5 (7.9%) 124 (9.7%) 0.6
    Unknown 0 1
Admitted to Neonatal Unit 10 (16%) 187 (15%) 0.8
    Unknown 1 6
1 n (%); Median (IQR)
2 Pearson’s Chi-squared test; Wilcoxon rank sum test; Fisher’s exact test
Characteristic ID, N = 1791 Non-ID, N = 1,1651 p-value2
C-section Delivery 46 (26%) 335 (29%) 0.4
    Unknown 2 10
Infant_GAw 40.00 (39.00, 41.00) 40.00 (39.00, 41.00) 0.6
    Unknown 2 5
Preterm 7 (4.0%) 58 (5.0%) 0.5
    Unknown 2 5
Apgar Score at 1min 9.00 (8.00, 9.00) 9.00 (9.00, 9.00) 0.13
    Unknown 3 17
Apgar Score at 5min 10.00 (9.00, 10.00) 10.00 (9.00, 10.00) 0.8
    Unknown 3 17
Birthweight 3,550 (3,240, 3,750) 3,480 (3,150, 3,800) 0.2
    Unknown 2 8
Birthweight Centile 51 (28, 73) 43 (21, 69) 0.034
    Unknown 2 9
Small for Gestational Age 16 (9.0%) 116 (10.0%) 0.7
    Unknown 1 1
LBW 8 (4.5%) 54 (4.7%) >0.9
    Unknown 2 8
Admitted to Neonatal Unit 24 (14%) 177 (15%) 0.6
    Unknown 2 6
1 n (%); Median (IQR)
2 Pearson’s Chi-squared test; Wilcoxon rank sum test
Characteristic ID, N = 3401 Non-ID, N = 3271 p-value2
C-section Delivery 102 (30%) 88 (27%) 0.4
    Unknown 1 0
Infant_GAw 40.00 (39.00, 41.00) 40.00 (39.00, 40.00) 0.005
    Unknown 1 0
Preterm 9 (2.7%) 19 (5.8%) 0.043
    Unknown 1 0
Apgar Score at 1min 9.00 (9.00, 9.00) 9.00 (9.00, 9.00) 0.2
    Unknown 2 0
Apgar Score at 5min 10.00 (9.00, 10.00) 10.00 (9.00, 10.00) 0.3
    Unknown 2 0
Birthweight 3,550 (3,260, 3,830) 3,430 (3,125, 3,750) 0.001
    Unknown 1 0
Birthweight Centile 48 (26, 73) 42 (22, 66) 0.062
    Unknown 1 0
Small for Gestational Age 28 (8.3%) 28 (8.6%) 0.9
    Unknown 1 0
LBW 5 (1.5%) 16 (4.9%) 0.012
    Unknown 1 0
Admitted to Neonatal Unit 46 (14%) 51 (16%) 0.5
    Unknown 1 0
1 n (%); Median (IQR)
2 Pearson’s Chi-squared test; Wilcoxon rank sum test

In order: Ferritin < 30µg/L @ 15weeks, 20 weeks, 33 weeks

Characteristic ID, N = 2771 Non-ID, N = 1,0601 p-value2
C-section Delivery 69 (25%) 310 (30%) 0.14
    Unknown 1 10
Infant_GAw 40.00 (39.00, 41.00) 40.00 (39.00, 41.00) 0.3
    Unknown 1 5
Preterm 8 (2.9%) 55 (5.2%) 0.11
    Unknown 1 5
Apgar Score at 1min 9.00 (8.00, 9.00) 9.00 (9.00, 9.00) 0.040
    Unknown 2 17
Apgar Score at 5min 10.00 (9.00, 10.00) 10.00 (9.00, 10.00) 0.2
    Unknown 2 17
Birthweight 3,520 (3,200, 3,793) 3,470 (3,150, 3,790) 0.2
    Unknown 1 8
Birthweight Centile 47 (26, 70) 43 (21, 69) 0.12
    Unknown 1 9
LBW 12 (4.3%) 48 (4.6%) 0.9
    Unknown 1 8
Small for Gestational Age 26 (9.4%) 103 (9.7%) 0.9
    Unknown 0 1
Admitted to Neonatal Unit 43 (16%) 154 (15%) 0.7
    Unknown 1 6
1 n (%); Median (IQR)
2 Pearson’s Chi-squared test; Wilcoxon rank sum test
Characteristic ID, N = 5681 Non-ID, N = 7761 p-value2
C-section Delivery 162 (29%) 219 (28%) >0.9
    Unknown 5 7
Infant_GAw 40.00 (39.00, 41.00) 40.00 (39.00, 41.00) 0.2
    Unknown 4 3
Preterm 19 (3.4%) 46 (6.0%) 0.030
    Unknown 4 3
Apgar Score at 1min 9.00 (9.00, 9.00) 9.00 (9.00, 9.00) 0.4
    Unknown 10 10
Apgar Score at 5min 10.00 (9.00, 10.00) 10.00 (9.00, 10.00) 0.6
    Unknown 10 10
Birthweight 3,520 (3,205, 3,810) 3,450 (3,130, 3,775) 0.021
    Unknown 5 5
Birthweight Centile 48 (26, 73) 41 (21, 68) 0.003
    Unknown 6 5
Small for Gestational Age 51 (9.0%) 81 (10%) 0.4
    Unknown 2 0
LBW 20 (3.6%) 42 (5.4%) 0.10
    Unknown 5 5
Admitted to Neonatal Unit 86 (15%) 115 (15%) 0.8
    Unknown 5 3
1 n (%); Median (IQR)
2 Pearson’s Chi-squared test; Wilcoxon rank sum test
Characteristic ID, N = 5581 Non-ID, N = 1091 p-value2
C-section Delivery 158 (28%) 32 (29%) 0.8
    Unknown 1 0
Infant_GAw 40.00 (39.00, 41.00) 40.00 (38.00, 40.00) 0.039
    Unknown 1 0
Preterm 20 (3.6%) 8 (7.3%) 0.11
    Unknown 1 0
Apgar Score at 1min 9.00 (9.00, 9.00) 9.00 (9.00, 9.00) 0.8
    Unknown 2 0
Apgar Score at 5min 10.00 (9.00, 10.00) 9.00 (9.00, 10.00) 0.3
    Unknown 2 0
Birthweight 3,500 (3,200, 3,780) 3,370 (3,080, 3,800) 0.064
    Unknown 1 0
Birthweight Centile 47 (25, 70) 40 (19, 69) 0.3
    Unknown 1 0
Small for Gestational Age 47 (8.4%) 9 (8.3%) >0.9
    Unknown 1 0
LBW 12 (2.2%) 9 (8.3%) 0.003
    Unknown 1 0
Admitted to Neonatal Unit 78 (14%) 19 (17%) 0.4
    Unknown 1 0
1 n (%); Median (IQR)
2 Pearson’s Chi-squared test; Wilcoxon rank sum test; Fisher’s exact test

Ferritin < 60µg/L at 15 week

Characteristic ID, N = 7471 Non-ID, N = 5901 p-value2
C-section Delivery 210 (28%) 169 (29%) 0.8
    Unknown 5 6
Infant_GAw 40.00 (39.00, 41.00) 40.00 (39.00, 41.00) 0.4
    Unknown 3 3
Preterm 29 (3.9%) 34 (5.8%) 0.11
    Unknown 3 3
Apgar Score at 1min 9.00 (9.00, 9.00) 9.00 (9.00, 9.00) 0.087
    Unknown 10 9
Apgar Score at 5min 10.00 (9.00, 10.00) 10.00 (9.00, 10.00) 0.5
    Unknown 10 9
Birthweight 3,490 (3,170, 3,760) 3,480 (3,150, 3,810) >0.9
    Unknown 4 5
Birthweight Centile 44 (22, 70) 43 (23, 68) 0.7
    Unknown 5 5
Small for Gestational Age 79 (11%) 50 (8.5%) 0.2
    Unknown 0 1
LBW 33 (4.4%) 27 (4.6%) 0.9
    Unknown 4 5
Admitted to Neonatal Unit 114 (15%) 83 (14%) 0.5
    Unknown 4 3
1 n (%); Median (IQR)
2 Pearson’s Chi-squared test; Wilcoxon rank sum test

Adjusted Tables for Inflammation (Filter out CRP > 10)

In order: Ferritin < 15µg/L @ 15weeks, 20 weeks, 33 weeks

Characteristic ID, N = 621 Non-ID, N = 1,2001 p-value2
C-section Delivery 13 (21%) 344 (29%) 0.2
    Unknown 1 10
Infant_GAw 40.00 (39.00, 41.00) 40.00 (39.00, 41.00) 0.3
    Unknown 1 5
Preterm 3 (4.9%) 56 (4.7%) 0.8
    Unknown 1 5
Apgar Score at 1min 9.00 (9.00, 9.00) 9.00 (9.00, 9.00) 0.2
    Unknown 1 18
Apgar Score at 5min 10.00 (9.00, 10.00) 10.00 (9.00, 10.00) 0.8
    Unknown 1 18
Birthweight 3,470 (3,250, 3,660) 3,480 (3,150, 3,800) 0.9
    Unknown 1 8
Birthweight Centile 46 (27, 65) 44 (22, 70) 0.8
    Unknown 1 9
LBW 6 (9.8%) 54 (4.5%) 0.066
    Unknown 1 8
Small for Gestational Age 5 (8.1%) 117 (9.8%) 0.7
    Unknown 0 1
Admitted to Neonatal Unit 10 (16%) 177 (15%) 0.7
    Unknown 1 6
1 n (%); Median (IQR)
2 Pearson’s Chi-squared test; Wilcoxon rank sum test; Fisher’s exact test
Characteristic ID, N = 1681 Non-ID, N = 1,0901 p-value2
C-section Delivery 42 (25%) 312 (29%) 0.3
    Unknown 2 8
Infant_GAw 40.00 (39.00, 41.00) 40.00 (39.00, 41.00) 0.8
    Unknown 2 5
Preterm 7 (4.2%) 54 (5.0%) 0.7
    Unknown 2 5
Apgar Score at 1min 9.00 (8.00, 9.00) 9.00 (9.00, 9.00) 0.063
    Unknown 2 15
Apgar Score at 5min 10.00 (9.00, 10.00) 10.00 (9.00, 10.00) 0.6
    Unknown 2 15
Birthweight 3,535 (3,243, 3,750) 3,480 (3,150, 3,800) 0.3
    Unknown 2 7
Birthweight Centile 54 (28, 74) 44 (22, 69) 0.029
    Unknown 2 8
Small for Gestational Age 13 (7.8%) 107 (9.8%) 0.4
    Unknown 1 1
LBW 8 (4.8%) 53 (4.9%) >0.9
    Unknown 2 7
Admitted to Neonatal Unit 24 (14%) 164 (15%) 0.8
    Unknown 2 5
1 n (%); Median (IQR)
2 Pearson’s Chi-squared test; Wilcoxon rank sum test
Characteristic ID, N = 3321 Non-ID, N = 3061 p-value2
C-section Delivery 100 (30%) 80 (26%) 0.3
    Unknown 1 0
Infant_GAw 40.00 (39.00, 41.00) 40.00 (39.00, 40.00) 0.012
    Unknown 1 0
Preterm 9 (2.7%) 17 (5.6%) 0.071
    Unknown 1 0
Apgar Score at 1min 9.00 (9.00, 9.00) 9.00 (9.00, 9.00) 0.14
    Unknown 2 0
Apgar Score at 5min 10.00 (9.00, 10.00) 10.00 (9.00, 10.00) 0.2
    Unknown 2 0
Birthweight 3,550 (3,260, 3,820) 3,435 (3,150, 3,750) 0.003
    Unknown 1 0
Birthweight Centile 48 (26, 73) 42 (21, 66) 0.060
    Unknown 1 0
Small for Gestational Age 26 (7.9%) 27 (8.8%) 0.7
    Unknown 1 0
LBW 5 (1.5%) 14 (4.6%) 0.023
    Unknown 1 0
Admitted to Neonatal Unit 45 (14%) 47 (15%) 0.5
    Unknown 1 0
1 n (%); Median (IQR)
2 Pearson’s Chi-squared test; Wilcoxon rank sum test

In order: Ferritin < 30µg/L @ 15weeks, 20 weeks, 33 weeks

Characteristic ID, N = 2691 Non-ID, N = 9931 p-value2
C-section Delivery 68 (25%) 289 (29%) 0.2
    Unknown 1 10
Infant_GAw 40.00 (39.00, 41.00) 40.00 (39.00, 41.00) 0.5
    Unknown 1 5
Preterm 8 (3.0%) 51 (5.2%) 0.14
    Unknown 1 5
Apgar Score at 1min 9.00 (8.00, 9.00) 9.00 (9.00, 9.00) 0.021
    Unknown 2 17
Apgar Score at 5min 10.00 (9.00, 10.00) 10.00 (9.00, 10.00) 0.3
    Unknown 2 17
Birthweight 3,515 (3,200, 3,790) 3,470 (3,150, 3,790) 0.2
    Unknown 1 8
Birthweight Centile 47 (26, 70) 43 (21, 69) 0.13
    Unknown 1 9
LBW 12 (4.5%) 48 (4.9%) 0.8
    Unknown 1 8
Small for Gestational Age 24 (8.9%) 98 (9.9%) 0.6
    Unknown 0 1
Admitted to Neonatal Unit 43 (16%) 144 (15%) 0.6
    Unknown 1 6
1 n (%); Median (IQR)
2 Pearson’s Chi-squared test; Wilcoxon rank sum test
Characteristic ID, N = 5421 Non-ID, N = 7161 p-value2
C-section Delivery 153 (28%) 201 (28%) >0.9
    Unknown 4 6
Infant_GAw 40.00 (39.00, 41.00) 40.00 (39.00, 41.00) 0.3
    Unknown 4 3
Preterm 19 (3.5%) 42 (5.9%) 0.055
    Unknown 4 3
Apgar Score at 1min 9.00 (9.00, 9.00) 9.00 (9.00, 9.00) 0.2
    Unknown 8 9
Apgar Score at 5min 10.00 (9.00, 10.00) 10.00 (9.00, 10.00) 0.5
    Unknown 8 9
Birthweight 3,520 (3,213, 3,810) 3,460 (3,140, 3,775) 0.037
    Unknown 4 5
Birthweight Centile 48 (26, 73) 42 (21, 68) 0.003
    Unknown 5 5
Small for Gestational Age 46 (8.5%) 74 (10%) 0.3
    Unknown 2 0
LBW 20 (3.7%) 41 (5.8%) 0.10
    Unknown 4 5
Admitted to Neonatal Unit 83 (15%) 105 (15%) 0.7
    Unknown 4 3
1 n (%); Median (IQR)
2 Pearson’s Chi-squared test; Wilcoxon rank sum test
Characteristic ID, N = 5371 Non-ID, N = 1011 p-value2
C-section Delivery 150 (28%) 30 (30%) 0.7
    Unknown 1 0
Infant_GAw 40.00 (39.00, 41.00) 40.00 (38.00, 40.00) 0.025
    Unknown 1 0
Preterm 19 (3.5%) 7 (6.9%) 0.2
    Unknown 1 0
Apgar Score at 1min 9.00 (9.00, 9.00) 9.00 (9.00, 9.00) 0.7
    Unknown 2 0
Apgar Score at 5min 10.00 (9.00, 10.00) 9.00 (9.00, 10.00) 0.3
    Unknown 2 0
Birthweight 3,505 (3,208, 3,783) 3,370 (3,130, 3,800) 0.10
    Unknown 1 0
Birthweight Centile 47 (25, 71) 40 (19, 69) 0.3
    Unknown 1 0
Small for Gestational Age 45 (8.4%) 8 (7.9%) 0.9
    Unknown 1 0
LBW 12 (2.2%) 7 (6.9%) 0.020
    Unknown 1 0
Admitted to Neonatal Unit 75 (14%) 17 (17%) 0.5
    Unknown 1 0
1 n (%); Median (IQR)
2 Pearson’s Chi-squared test; Wilcoxon rank sum test; Fisher’s exact test

Ferritin < 60µg/L at 15 week

Characteristic ID, N = 7181 Non-ID, N = 5441 p-value2
C-section Delivery 198 (28%) 159 (30%) 0.5
    Unknown 5 6
Infant_GAw 40.00 (39.00, 41.00) 40.00 (39.00, 41.00) 0.6
    Unknown 3 3
Preterm 29 (4.1%) 30 (5.5%) 0.2
    Unknown 3 3
Apgar Score at 1min 9.00 (9.00, 9.00) 9.00 (9.00, 9.00) 0.054
    Unknown 10 9
Apgar Score at 5min 10.00 (9.00, 10.00) 10.00 (9.00, 10.00) 0.6
    Unknown 10 9
Birthweight 3,485 (3,170, 3,760) 3,470 (3,150, 3,810) >0.9
    Unknown 4 5
Birthweight Centile 45 (22, 70) 44 (22, 68) 0.5
    Unknown 5 5
Small for Gestational Age 74 (10%) 48 (8.8%) 0.4
    Unknown 0 1
LBW 33 (4.6%) 27 (5.0%) 0.8
    Unknown 4 5
Admitted to Neonatal Unit 110 (15%) 77 (14%) 0.6
    Unknown 4 3
1 n (%); Median (IQR)
2 Pearson’s Chi-squared test; Wilcoxon rank sum test

Adjusted Tables for Inflammation (Filter out CRP > 10) & Iron Overload (Ferritin > 150)

In order: Ferritin < 15µg/L @ 15weeks, 20 weeks, 33 weeks

Characteristic ID, N = 621 Non-ID, N = 1,1601 p-value2
C-section Delivery 13 (21%) 330 (29%) 0.2
    Unknown 1 10
Infant_GAw 40.00 (39.00, 41.00) 40.00 (39.00, 41.00) 0.3
    Unknown 1 5
Preterm 3 (4.9%) 54 (4.7%) 0.8
    Unknown 1 5
Apgar Score at 1min 9.00 (9.00, 9.00) 9.00 (9.00, 9.00) 0.2
    Unknown 1 18
Apgar Score at 5min 10.00 (9.00, 10.00) 10.00 (9.00, 10.00) 0.7
    Unknown 1 18
Birthweight 3,470 (3,250, 3,660) 3,480 (3,160, 3,800) 0.8
    Unknown 1 8
Birthweight Centile 46 (27, 65) 45 (22, 70) >0.9
    Unknown 1 9
LBW 6 (9.8%) 50 (4.3%) 0.057
    Unknown 1 8
Small for Gestational Age 5 (8.1%) 110 (9.5%) 0.7
    Unknown 0 1
Admitted to Neonatal Unit 10 (16%) 170 (15%) 0.7
    Unknown 1 6
1 n (%); Median (IQR)
2 Pearson’s Chi-squared test; Wilcoxon rank sum test; Fisher’s exact test
Characteristic ID, N = 1681 Non-ID, N = 1,0771 p-value2
C-section Delivery 42 (25%) 307 (29%) 0.4
    Unknown 2 8
Infant_GAw 40.00 (39.00, 41.00) 40.00 (39.00, 41.00) 0.8
    Unknown 2 5
Preterm 7 (4.2%) 53 (4.9%) 0.7
    Unknown 2 5
Apgar Score at 1min 9.00 (8.00, 9.00) 9.00 (9.00, 9.00) 0.060
    Unknown 2 15
Apgar Score at 5min 10.00 (9.00, 10.00) 10.00 (9.00, 10.00) 0.7
    Unknown 2 15
Birthweight 3,535 (3,243, 3,750) 3,480 (3,150, 3,800) 0.3
    Unknown 2 7
Birthweight Centile 54 (28, 74) 44 (22, 69) 0.032
    Unknown 2 8
Small for Gestational Age 13 (7.8%) 106 (9.9%) 0.4
    Unknown 1 1
LBW 8 (4.8%) 52 (4.9%) >0.9
    Unknown 2 7
Admitted to Neonatal Unit 24 (14%) 162 (15%) 0.8
    Unknown 2 5
1 n (%); Median (IQR)
2 Pearson’s Chi-squared test; Wilcoxon rank sum test
Characteristic ID, N = 3321 Non-ID, N = 3041 p-value2
C-section Delivery 100 (30%) 79 (26%) 0.2
    Unknown 1 0
Infant_GAw 40.00 (39.00, 41.00) 40.00 (39.00, 40.00) 0.011
    Unknown 1 0
Preterm 9 (2.7%) 17 (5.6%) 0.068
    Unknown 1 0
Apgar Score at 1min 9.00 (9.00, 9.00) 9.00 (9.00, 9.00) 0.15
    Unknown 2 0
Apgar Score at 5min 10.00 (9.00, 10.00) 10.00 (9.00, 10.00) 0.2
    Unknown 2 0
Birthweight 3,550 (3,260, 3,820) 3,435 (3,150, 3,750) 0.004
    Unknown 1 0
Birthweight Centile 48 (26, 73) 43 (22, 66) 0.071
    Unknown 1 0
Small for Gestational Age 26 (7.9%) 26 (8.6%) 0.7
    Unknown 1 0
LBW 5 (1.5%) 14 (4.6%) 0.022
    Unknown 1 0
Admitted to Neonatal Unit 45 (14%) 47 (15%) 0.5
    Unknown 1 0
1 n (%); Median (IQR)
2 Pearson’s Chi-squared test; Wilcoxon rank sum test

In order: Ferritin < 30µg/L @ 15weeks, 20 weeks, 33 weeks

Characteristic ID, N = 2691 Non-ID, N = 9531 p-value2
C-section Delivery 68 (25%) 275 (29%) 0.2
    Unknown 1 10
Infant_GAw 40.00 (39.00, 41.00) 40.00 (39.00, 41.00) 0.5
    Unknown 1 5
Preterm 8 (3.0%) 49 (5.2%) 0.14
    Unknown 1 5
Apgar Score at 1min 9.00 (8.00, 9.00) 9.00 (9.00, 9.00) 0.020
    Unknown 2 17
Apgar Score at 5min 10.00 (9.00, 10.00) 10.00 (9.00, 10.00) 0.3
    Unknown 2 17
Birthweight 3,515 (3,200, 3,790) 3,470 (3,150, 3,800) 0.3
    Unknown 1 8
Birthweight Centile 47 (26, 70) 44 (21, 70) 0.2
    Unknown 1 9
LBW 12 (4.5%) 44 (4.7%) >0.9
    Unknown 1 8
Small for Gestational Age 24 (8.9%) 91 (9.6%) 0.8
    Unknown 0 1
Admitted to Neonatal Unit 43 (16%) 137 (14%) 0.5
    Unknown 1 6
1 n (%); Median (IQR)
2 Pearson’s Chi-squared test; Wilcoxon rank sum test
Characteristic ID, N = 5421 Non-ID, N = 7031 p-value2
C-section Delivery 153 (28%) 196 (28%) >0.9
    Unknown 4 6
Infant_GAw 40.00 (39.00, 41.00) 40.00 (39.00, 41.00) 0.3
    Unknown 4 3
Preterm 19 (3.5%) 41 (5.9%) 0.059
    Unknown 4 3
Apgar Score at 1min 9.00 (9.00, 9.00) 9.00 (9.00, 9.00) 0.2
    Unknown 8 9
Apgar Score at 5min 10.00 (9.00, 10.00) 10.00 (9.00, 10.00) 0.5
    Unknown 8 9
Birthweight 3,520 (3,213, 3,810) 3,455 (3,140, 3,778) 0.035
    Unknown 4 5
Birthweight Centile 48 (26, 73) 42 (21, 68) 0.004
    Unknown 5 5
Small for Gestational Age 46 (8.5%) 73 (10%) 0.3
    Unknown 2 0
LBW 20 (3.7%) 40 (5.7%) 0.10
    Unknown 4 5
Admitted to Neonatal Unit 83 (15%) 103 (15%) 0.7
    Unknown 4 3
1 n (%); Median (IQR)
2 Pearson’s Chi-squared test; Wilcoxon rank sum test
Characteristic ID, N = 5371 Non-ID, N = 991 p-value2
C-section Delivery 150 (28%) 29 (29%) 0.8
    Unknown 1 0
Infant_GAw 40.00 (39.00, 41.00) 40.00 (38.00, 40.00) 0.021
    Unknown 1 0
Preterm 19 (3.5%) 7 (7.1%) 0.2
    Unknown 1 0
Apgar Score at 1min 9.00 (9.00, 9.00) 9.00 (9.00, 9.00) 0.7
    Unknown 2 0
Apgar Score at 5min 10.00 (9.00, 10.00) 9.00 (9.00, 10.00) 0.3
    Unknown 2 0
Birthweight 3,505 (3,208, 3,783) 3,370 (3,140, 3,800) 0.11
    Unknown 1 0
Birthweight Centile 47 (25, 71) 40 (19, 69) 0.4
    Unknown 1 0
Small for Gestational Age 45 (8.4%) 7 (7.1%) 0.7
    Unknown 1 0
LBW 12 (2.2%) 7 (7.1%) 0.018
    Unknown 1 0
Admitted to Neonatal Unit 75 (14%) 17 (17%) 0.4
    Unknown 1 0
1 n (%); Median (IQR)
2 Pearson’s Chi-squared test; Wilcoxon rank sum test; Fisher’s exact test

Ferritin < 60µg/L at 15 week

Characteristic ID, N = 7181 Non-ID, N = 5041 p-value2
C-section Delivery 198 (28%) 145 (29%) 0.6
    Unknown 5 6
Infant_GAw 40.00 (39.00, 41.00) 40.00 (39.00, 41.00) 0.6
    Unknown 3 3
Preterm 29 (4.1%) 28 (5.6%) 0.2
    Unknown 3 3
Apgar Score at 1min 9.00 (9.00, 9.00) 9.00 (9.00, 9.00) 0.046
    Unknown 10 9
Apgar Score at 5min 10.00 (9.00, 10.00) 10.00 (9.00, 10.00) 0.8
    Unknown 10 9
Birthweight 3,485 (3,170, 3,760) 3,480 (3,160, 3,825) 0.8
    Unknown 4 5
Birthweight Centile 45 (22, 70) 45 (23, 69) >0.9
    Unknown 5 5
Small for Gestational Age 74 (10%) 41 (8.2%) 0.2
    Unknown 0 1
LBW 33 (4.6%) 23 (4.6%) >0.9
    Unknown 4 5
Admitted to Neonatal Unit 110 (15%) 70 (14%) 0.5
    Unknown 4 3
1 n (%); Median (IQR)
2 Pearson’s Chi-squared test; Wilcoxon rank sum test

Adjusted Tables for Inflammation (Filter out CRP > 10) & Iron Overload (Ferritin > 200)

In order: Ferritin < 15µg/L @ 15weeks, 20 weeks, 33 weeks

Characteristic ID, N = 621 Non-ID, N = 1,1891 p-value2
C-section Delivery 13 (21%) 339 (29%) 0.2
    Unknown 1 10
Infant_GAw 40.00 (39.00, 41.00) 40.00 (39.00, 41.00) 0.3
    Unknown 1 5
Preterm 3 (4.9%) 55 (4.6%) 0.8
    Unknown 1 5
Apgar Score at 1min 9.00 (9.00, 9.00) 9.00 (9.00, 9.00) 0.2
    Unknown 1 18
Apgar Score at 5min 10.00 (9.00, 10.00) 10.00 (9.00, 10.00) 0.8
    Unknown 1 18
Birthweight 3,470 (3,250, 3,660) 3,480 (3,160, 3,800) 0.9
    Unknown 1 8
Birthweight Centile 46 (27, 65) 44 (22, 70) 0.8
    Unknown 1 9
LBW 6 (9.8%) 53 (4.5%) 0.064
    Unknown 1 8
Small for Gestational Age 5 (8.1%) 115 (9.7%) 0.7
    Unknown 0 1
Admitted to Neonatal Unit 10 (16%) 175 (15%) 0.7
    Unknown 1 6
1 n (%); Median (IQR)
2 Pearson’s Chi-squared test; Wilcoxon rank sum test; Fisher’s exact test
Characteristic ID, N = 1681 Non-ID, N = 1,0831 p-value2
C-section Delivery 42 (25%) 309 (29%) 0.4
    Unknown 2 8
Infant_GAw 40.00 (39.00, 41.00) 40.00 (39.00, 41.00) 0.8
    Unknown 2 5
Preterm 7 (4.2%) 53 (4.9%) 0.7
    Unknown 2 5
Apgar Score at 1min 9.00 (8.00, 9.00) 9.00 (9.00, 9.00) 0.064
    Unknown 2 15
Apgar Score at 5min 10.00 (9.00, 10.00) 10.00 (9.00, 10.00) 0.6
    Unknown 2 15
Birthweight 3,535 (3,243, 3,750) 3,475 (3,150, 3,800) 0.3
    Unknown 2 7
Birthweight Centile 54 (28, 74) 44 (22, 69) 0.030
    Unknown 2 8
Small for Gestational Age 13 (7.8%) 106 (9.8%) 0.4
    Unknown 1 1
LBW 8 (4.8%) 52 (4.8%) >0.9
    Unknown 2 7
Admitted to Neonatal Unit 24 (14%) 162 (15%) 0.8
    Unknown 2 5
1 n (%); Median (IQR)
2 Pearson’s Chi-squared test; Wilcoxon rank sum test
Characteristic ID, N = 3321 Non-ID, N = 3061 p-value2
C-section Delivery 100 (30%) 80 (26%) 0.3
    Unknown 1 0
Infant_GAw 40.00 (39.00, 41.00) 40.00 (39.00, 40.00) 0.012
    Unknown 1 0
Preterm 9 (2.7%) 17 (5.6%) 0.071
    Unknown 1 0
Apgar Score at 1min 9.00 (9.00, 9.00) 9.00 (9.00, 9.00) 0.14
    Unknown 2 0
Apgar Score at 5min 10.00 (9.00, 10.00) 10.00 (9.00, 10.00) 0.2
    Unknown 2 0
Birthweight 3,550 (3,260, 3,820) 3,435 (3,150, 3,750) 0.003
    Unknown 1 0
Birthweight Centile 48 (26, 73) 42 (21, 66) 0.060
    Unknown 1 0
Small for Gestational Age 26 (7.9%) 27 (8.8%) 0.7
    Unknown 1 0
LBW 5 (1.5%) 14 (4.6%) 0.023
    Unknown 1 0
Admitted to Neonatal Unit 45 (14%) 47 (15%) 0.5
    Unknown 1 0
1 n (%); Median (IQR)
2 Pearson’s Chi-squared test; Wilcoxon rank sum test

In order: Ferritin < 30µg/L @ 15weeks, 20 weeks, 33 weeks

Characteristic ID, N = 2691 Non-ID, N = 9821 p-value2
C-section Delivery 68 (25%) 284 (29%) 0.2
    Unknown 1 10
Infant_GAw 40.00 (39.00, 41.00) 40.00 (39.00, 41.00) 0.5
    Unknown 1 5
Preterm 8 (3.0%) 50 (5.1%) 0.14
    Unknown 1 5
Apgar Score at 1min 9.00 (8.00, 9.00) 9.00 (9.00, 9.00) 0.021
    Unknown 2 17
Apgar Score at 5min 10.00 (9.00, 10.00) 10.00 (9.00, 10.00) 0.3
    Unknown 2 17
Birthweight 3,515 (3,200, 3,790) 3,470 (3,150, 3,798) 0.2
    Unknown 1 8
Birthweight Centile 47 (26, 70) 43 (21, 70) 0.14
    Unknown 1 9
LBW 12 (4.5%) 47 (4.8%) 0.8
    Unknown 1 8
Small for Gestational Age 24 (8.9%) 96 (9.8%) 0.7
    Unknown 0 1
Admitted to Neonatal Unit 43 (16%) 142 (15%) 0.5
    Unknown 1 6
1 n (%); Median (IQR)
2 Pearson’s Chi-squared test; Wilcoxon rank sum test
Characteristic ID, N = 5421 Non-ID, N = 7091 p-value2
C-section Delivery 153 (28%) 198 (28%) >0.9
    Unknown 4 6
Infant_GAw 40.00 (39.00, 41.00) 40.00 (39.00, 41.00) 0.3
    Unknown 4 3
Preterm 19 (3.5%) 41 (5.8%) 0.063
    Unknown 4 3
Apgar Score at 1min 9.00 (9.00, 9.00) 9.00 (9.00, 9.00) 0.3
    Unknown 8 9
Apgar Score at 5min 10.00 (9.00, 10.00) 10.00 (9.00, 10.00) 0.4
    Unknown 8 9
Birthweight 3,520 (3,213, 3,810) 3,450 (3,140, 3,773) 0.035
    Unknown 4 5
Birthweight Centile 48 (26, 73) 42 (21, 68) 0.003
    Unknown 5 5
Small for Gestational Age 46 (8.5%) 73 (10%) 0.3
    Unknown 2 0
LBW 20 (3.7%) 40 (5.7%) 0.11
    Unknown 4 5
Admitted to Neonatal Unit 83 (15%) 103 (15%) 0.7
    Unknown 4 3
1 n (%); Median (IQR)
2 Pearson’s Chi-squared test; Wilcoxon rank sum test
Characteristic ID, N = 5371 Non-ID, N = 1011 p-value2
C-section Delivery 150 (28%) 30 (30%) 0.7
    Unknown 1 0
Infant_GAw 40.00 (39.00, 41.00) 40.00 (38.00, 40.00) 0.025
    Unknown 1 0
Preterm 19 (3.5%) 7 (6.9%) 0.2
    Unknown 1 0
Apgar Score at 1min 9.00 (9.00, 9.00) 9.00 (9.00, 9.00) 0.7
    Unknown 2 0
Apgar Score at 5min 10.00 (9.00, 10.00) 9.00 (9.00, 10.00) 0.3
    Unknown 2 0
Birthweight 3,505 (3,208, 3,783) 3,370 (3,130, 3,800) 0.10
    Unknown 1 0
Birthweight Centile 47 (25, 71) 40 (19, 69) 0.3
    Unknown 1 0
Small for Gestational Age 45 (8.4%) 8 (7.9%) 0.9
    Unknown 1 0
LBW 12 (2.2%) 7 (6.9%) 0.020
    Unknown 1 0
Admitted to Neonatal Unit 75 (14%) 17 (17%) 0.5
    Unknown 1 0
1 n (%); Median (IQR)
2 Pearson’s Chi-squared test; Wilcoxon rank sum test; Fisher’s exact test

Ferritin < 60µg/L at 15 week

Characteristic ID, N = 7181 Non-ID, N = 5331 p-value2
C-section Delivery 198 (28%) 154 (29%) 0.6
    Unknown 5 6
Infant_GAw 40.00 (39.00, 41.00) 40.00 (39.00, 41.00) 0.6
    Unknown 3 3
Preterm 29 (4.1%) 29 (5.5%) 0.2
    Unknown 3 3
Apgar Score at 1min 9.00 (9.00, 9.00) 9.00 (9.00, 9.00) 0.052
    Unknown 10 9
Apgar Score at 5min 10.00 (9.00, 10.00) 10.00 (9.00, 10.00) 0.7
    Unknown 10 9
Birthweight 3,485 (3,170, 3,760) 3,465 (3,150, 3,813) >0.9
    Unknown 4 5
Birthweight Centile 45 (22, 70) 44 (22, 69) 0.6
    Unknown 5 5
Small for Gestational Age 74 (10%) 46 (8.6%) 0.3
    Unknown 0 1
LBW 33 (4.6%) 26 (4.9%) 0.8
    Unknown 4 5
Admitted to Neonatal Unit 110 (15%) 75 (14%) 0.5
    Unknown 4 3
1 n (%); Median (IQR)
2 Pearson’s Chi-squared test; Wilcoxon rank sum test

Correlation Plots for Birth Outcomes

Correlation Table for Maternal/Cord biomarkers

Maternal Biomarker Cord Ferritin Cord sTFR Cord TBI Visit
Ferritin 0.07 0.02 0.04 15w
sTFR -0.03 0.06 -0.05 15w
TBI 0.07 0.01 0.05 15w
Ferritin 0.04 0 0.03 20w
sTFR -0.01 0.03 -0.01 20w
TBI 0.04 0 0.03 20w
Ferritin 0.12 -0.09 0.13 33w
sTFR -0.02 0.08 -0.05 33w
TBI 0.1 -0.09 0.11 33w

Notes on Outcomes tables (how many people filtered out from CRP/iron overload)

Number of people filtered out at each step for each visit:

  • 15w: 1327 total with iron observation. 75 taken out with CRP ≥ 10. Further 11 taken out with ≥ 200. Further 29 taken out with >150 (total of 40 greater than 150)

  • 20w: 1334 total with iron. 86 taken out with CRP ≥ 10. Further 7 taken out with Ferritin ≥ 200. Further 6 taken out with > 150 (Total of 13 greater than 150)

  • 33w: 667 total with iron. 29 taken out with CRP ≥ 10. 0 with Ferritin ≥ 200. 2 taken out with ferritin ≥ 150

Logistic Regression models

Paper shared with team: univariate analysis and then multivariate analysis adjusting for maternal age, gestational age at blood test, body weight, parity, smoking during pregnancy, private versus public health care, low socioeconomic status and log C-reactive protein levels.

First we present univariate analyses with the respective total samples

Characteristic log(OR)1 95% CI1 p-value
Ferritin_less15_14_16w


    ID — —
    Non-ID -0.88 -1.7, 0.11 0.052
1 OR = Odds Ratio, CI = Confidence Interval
Characteristic log(OR)1 95% CI1 p-value
Ferritin_less30_14_16w


    ID — —
    Non-ID 0.05 -0.56, 0.74 0.9
1 OR = Odds Ratio, CI = Confidence Interval
Characteristic log(OR)1 95% CI1 p-value
Ferritin_less15_19_21w


    ID — —
    Non-ID 0.03 -0.67, 0.87 >0.9
1 OR = Odds Ratio, CI = Confidence Interval
Characteristic log(OR)1 95% CI1 p-value
Ferritin_less30_19_21w


    ID — —
    Non-ID 0.45 -0.08, 1.0 0.11
1 OR = Odds Ratio, CI = Confidence Interval
Characteristic log(OR)1 95% CI1 p-value
Ferritin_less15_32_34w


    ID — —
    Non-ID 1.2 0.28, 2.4 0.017
1 OR = Odds Ratio, CI = Confidence Interval
Characteristic log(OR)1 95% CI1 p-value
Ferritin_less30_32_34w


    ID — —
    Non-ID 1.4 0.49, 2.3 0.002
1 OR = Odds Ratio, CI = Confidence Interval

  • Marginally significant association at the 15w visit for mothers < 15 (p = .052). Mothers with higher iron have lower rates of LBW

  • Significant associations at the 33w visit for both ID thresholds. Mothers with ID have lower rates of LBW.

Now, we present univariate analyses with the reduced sample (remove CRP > 10 and Ferritin > 150)

Characteristic log(OR)1 95% CI1 p-value
Ferritin_less15_14_16w


    ID — —
    Non-ID -0.88 -1.7, 0.11 0.053
1 OR = Odds Ratio, CI = Confidence Interval
Characteristic log(OR)1 95% CI1 p-value
Ferritin_less30_14_16w


    ID — —
    Non-ID 0.04 -0.58, 0.74 >0.9
1 OR = Odds Ratio, CI = Confidence Interval
Characteristic log(OR)1 95% CI1 p-value
Ferritin_less15_19_21w


    ID — —
    Non-ID 0.01 -0.70, 0.85 >0.9
1 OR = Odds Ratio, CI = Confidence Interval
Characteristic log(OR)1 95% CI1 p-value
Ferritin_less30_19_21w


    ID — —
    Non-ID 0.45 -0.08, 1.0 0.11
1 OR = Odds Ratio, CI = Confidence Interval
Characteristic log(OR)1 95% CI1 p-value
Ferritin_less15_32_34w


    ID — —
    Non-ID 1.1 0.17, 2.3 0.030
1 OR = Odds Ratio, CI = Confidence Interval
Characteristic log(OR)1 95% CI1 p-value
Ferritin_less30_32_34w


    ID — —
    Non-ID 1.2 0.19, 2.1 0.014
1 OR = Odds Ratio, CI = Confidence Interval

  • Again, Marginally significant association at the 15w visit for mothers < 15 (p = .052). Mothers with higher iron have lower rates of LBW

  • Significant associations remained at the 33w visit for both ID thresholds. Mothers with ID have lower rates of LBW

Univariate relationships with covariates

  • Ethnicity - Caucasian Y or N

  • Country of birth - Ireland Y or N

  • Relationship status - stable/married Y or N

  • Household income - <€21,000 per annum Y or N

  • Education - university level Y or N

  • Maternal age at delivery (years)

  • Smoker at 15 weeks gestation – Y or N

  • Alcohol consumer at 15 weeks gestation – Y or N

  • Obese (BMI>30 kg/m2) at 15 weeks gestation – Y or N

  • Iron supplement user pre- or early pregnancy – Y or N

  • Mode of delivery - C-section Y or N

  • Gestational diabetes – Y or N

  • Gestational hypertension – Y or N

  • Pre-eclampsia – Y or N

  • Gravidity

  • Maternity care – public or private (variable: Maternity_care)

  • Infant gender

  • Gestational age (weeks)

  • Small-for-gestational age – Y or N (not sure about this one but can see what it looks like in univariate)

Characteristic log(OR)1 95% CI1 p-value
Ethnicity_White 0.56 -1.0, 3.4 0.6
1 OR = Odds Ratio, CI = Confidence Interval
Characteristic log(OR)1 95% CI1 p-value
CountryofBirth_Ireland 0.54 -0.12, 1.3 0.14
1 OR = Odds Ratio, CI = Confidence Interval
Characteristic log(OR)1 95% CI1 p-value
Relationship_Stable -0.07 -0.91, 1.0 0.9
1 OR = Odds Ratio, CI = Confidence Interval
Characteristic log(OR)1 95% CI1 p-value
IncomeHousehold_less21k -0.19 -1.3, 0.65 0.7
1 OR = Odds Ratio, CI = Confidence Interval
Characteristic log(OR)1 95% CI1 p-value
University_education -0.09 -0.59, 0.45 0.7
1 OR = Odds Ratio, CI = Confidence Interval
Characteristic log(OR)1 95% CI1 p-value
Maternal_Age_Delivery -0.01 -0.06, 0.05 0.8
1 OR = Odds Ratio, CI = Confidence Interval
Characteristic log(OR)1 95% CI1 p-value
Smoker_1st_trim 0.50 -0.03, 1.0 0.054
1 OR = Odds Ratio, CI = Confidence Interval
Characteristic log(OR)1 95% CI1 p-value
Alcohol_1sttrim -0.29 -0.78, 0.21 0.2
1 OR = Odds Ratio, CI = Confidence Interval
Characteristic log(OR)1 95% CI1 p-value
Maternal_Obesity_14_16w 0.44 -0.25, 1.0 0.2
1 OR = Odds Ratio, CI = Confidence Interval
Characteristic log(OR)1 95% CI1 p-value
IronSupp_PreEarlyPreg -0.11 -0.63, 0.45 0.7
1 OR = Odds Ratio, CI = Confidence Interval
Characteristic log(OR)1 95% CI1 p-value
C-section Delivery


    No — —
    Yes 0.18 -0.35, 0.68 0.5
1 OR = Odds Ratio, CI = Confidence Interval
Characteristic log(OR)1 95% CI1 p-value
GestationalDiabetes 0.21 -0.05, 0.49 0.12
1 OR = Odds Ratio, CI = Confidence Interval
Characteristic log(OR)1 95% CI1 p-value
Gestationalhypertension 0.37 -0.47, 1.1 0.3
1 OR = Odds Ratio, CI = Confidence Interval
Characteristic log(OR)1 95% CI1 p-value
Preeclampsia 2.0 1.4, 2.7 <0.001
1 OR = Odds Ratio, CI = Confidence Interval
Characteristic log(OR)1 95% CI1 p-value
Gravidity -0.70 -1.6, -0.03 0.069
1 OR = Odds Ratio, CI = Confidence Interval
Characteristic log(OR)1 95% CI1 p-value
Maternity_care -0.87 -3.7, 0.68 0.4
1 OR = Odds Ratio, CI = Confidence Interval
Characteristic log(OR)1 95% CI1 p-value
Sex -0.06 -0.55, 0.42 0.8
1 OR = Odds Ratio, CI = Confidence Interval
Characteristic log(OR)1 95% CI1 p-value
Infant_GAw -1.1 -1.3, -0.94 <0.001
1 OR = Odds Ratio, CI = Confidence Interval
Characteristic log(OR)1 95% CI1 p-value
Small for Gestational Age


    No — —
    Yes 3.2 2.7, 3.7 <0.001
1 OR = Odds Ratio, CI = Confidence Interval

Multivariate Models

From the univariate analyses, we can see that smoking, Gest diabetes, pre-eclampsia, gravidity, Gestational Age, and SGA all were below (or right above) p = 0.10.

So, the final covariates we will include are: Gest diabetes, pre-eclampsia, gravidity, BOTH Gestational Age and SGA, and Iron Supplement status in early pregnancy.

We present each of the iron deficiency threshold models for each time point, both for the full sample and the sample with Ferritin < 150 and CRP < 10 concurrently.

Full sample models

Characteristic log(OR)1 95% CI1 p-value
Ferritin_less15_14_16w


    ID — —
    Non-ID -0.94 -3.4, 1.3 0.4
Smoker_1st_trim 0.53 -0.70, 1.7 0.4
GestationalDiabetes 0.42 -0.14, 1.0 0.2
Preeclampsia -0.34 -2.3, 1.4 0.7
Gravidity -2.1 -3.9, -0.51 0.016
Infant_GAw -1.9 -2.5, -1.4 <0.001
Small for Gestational Age


    No — —
    Yes 6.5 4.8, 8.8 <0.001
IronSupp_PreEarlyPreg 0.83 -0.47, 2.3 0.2
1 OR = Odds Ratio, CI = Confidence Interval
Characteristic log(OR)1 95% CI1 p-value
Ferritin_less30_14_16w


    ID — —
    Non-ID -0.95 -2.3, 0.39 0.2
Smoker_1st_trim 0.53 -0.71, 1.8 0.4
GestationalDiabetes 0.39 -0.17, 0.99 0.2
Preeclampsia -0.36 -2.3, 1.4 0.7
Gravidity -2.0 -3.8, -0.45 0.019
Infant_GAw -1.9 -2.5, -1.5 <0.001
Small for Gestational Age


    No — —
    Yes 6.7 4.9, 9.1 <0.001
IronSupp_PreEarlyPreg 0.87 -0.43, 2.3 0.2
1 OR = Odds Ratio, CI = Confidence Interval
Characteristic log(OR)1 95% CI1 p-value
Ferritin_less15_19_21w


    ID — —
    Non-ID -0.09 -1.7, 1.6 >0.9
Smoker_1st_trim 0.52 -0.69, 1.7 0.4
GestationalDiabetes 0.41 -0.14, 1.0 0.2
Preeclampsia -0.38 -2.3, 1.4 0.7
Gravidity -2.1 -4.0, -0.59 0.012
Infant_GAw -1.9 -2.5, -1.5 <0.001
Small for Gestational Age


    No — —
    Yes 6.6 4.9, 8.9 <0.001
IronSupp_PreEarlyPreg 0.83 -0.46, 2.3 0.2
1 OR = Odds Ratio, CI = Confidence Interval
Characteristic log(OR)1 95% CI1 p-value
Ferritin_less30_19_21w


    ID — —
    Non-ID 0.00 -1.1, 1.1 >0.9
Smoker_1st_trim 0.53 -0.69, 1.7 0.4
GestationalDiabetes 0.41 -0.14, 1.0 0.2
Preeclampsia -0.38 -2.4, 1.4 0.7
Gravidity -2.2 -4.0, -0.58 0.013
Infant_GAw -1.9 -2.5, -1.5 <0.001
Small for Gestational Age


    No — —
    Yes 6.6 4.9, 8.9 <0.001
IronSupp_PreEarlyPreg 0.82 -0.47, 2.2 0.2
1 OR = Odds Ratio, CI = Confidence Interval
Characteristic log(OR)1 95% CI1 p-value
Ferritin_less15_32_34w


    ID — —
    Non-ID 3.6 1.0, 7.2 0.021
Smoker_1st_trim 0.92 -1.2, 3.0 0.4
GestationalDiabetes 1.1 0.07, 2.4 0.057
Preeclampsia -1.2 -6.9, 3.7 0.7
Gravidity -4.2 -8.7, -1.1 0.025
Infant_GAw -2.0 -3.2, -1.3 <0.001
Small for Gestational Age


    No — —
    Yes 7.7 4.6, 13 <0.001
IronSupp_PreEarlyPreg 0.33 -1.9, 2.9 0.8
1 OR = Odds Ratio, CI = Confidence Interval
Characteristic log(OR)1 95% CI1 p-value
Ferritin_less30_32_34w


    ID — —
    Non-ID 3.0 0.91, 5.7 0.009
Smoker_1st_trim 0.96 -1.4, 3.3 0.4
GestationalDiabetes 1.1 0.15, 2.3 0.041
Preeclampsia -1.1 -8.3, 4.6 0.8
Gravidity -3.0 -6.8, -0.40 0.051
Infant_GAw -2.0 -3.2, -1.2 <0.001
Small for Gestational Age


    No — —
    Yes 7.2 4.4, 12 <0.001
IronSupp_PreEarlyPreg 0.17 -2.3, 2.9 0.9
1 OR = Odds Ratio, CI = Confidence Interval

Models that exclude participants with Ferritin > 150 and/or CRP >10

Characteristic log(OR)1 95% CI1 p-value
Ferritin_less15_14_16w


    ID — —
    Non-ID -0.82 -3.3, 1.4 0.5
Smoker_1st_trim 0.19 -1.1, 1.5 0.8
GestationalDiabetes 0.45 -0.14, 1.1 0.15
Preeclampsia -0.52 -2.5, 1.2 0.6
Gravidity -2.0 -3.9, -0.46 0.020
Infant_GAw -1.9 -2.5, -1.4 <0.001
Small for Gestational Age


    No — —
    Yes 6.6 4.8, 9.0 <0.001
IronSupp_PreEarlyPreg 1.2 -0.22, 2.8 0.12
1 OR = Odds Ratio, CI = Confidence Interval
Characteristic log(OR)1 95% CI1 p-value
Ferritin_less30_14_16w


    ID — —
    Non-ID -0.85 -2.2, 0.51 0.2
Smoker_1st_trim 0.18 -1.2, 1.5 0.8
GestationalDiabetes 0.44 -0.16, 1.1 0.2
Preeclampsia -0.54 -2.5, 1.2 0.6
Gravidity -2.0 -3.8, -0.39 0.024
Infant_GAw -1.9 -2.5, -1.5 <0.001
Small for Gestational Age


    No — —
    Yes 6.7 4.9, 9.2 <0.001
IronSupp_PreEarlyPreg 1.2 -0.17, 2.8 0.10
1 OR = Odds Ratio, CI = Confidence Interval
Characteristic log(OR)1 95% CI1 p-value
Ferritin_less15_19_21w


    ID — —
    Non-ID -0.10 -1.8, 1.7 >0.9
Smoker_1st_trim 0.24 -1.0, 1.5 0.7
GestationalDiabetes 0.39 -0.19, 1.0 0.2
Preeclampsia -0.55 -2.6, 1.3 0.6
Gravidity -2.2 -4.0, -0.55 0.015
Infant_GAw -1.9 -2.5, -1.4 <0.001
Small for Gestational Age


    No — —
    Yes 6.8 5.0, 9.2 <0.001
IronSupp_PreEarlyPreg 1.1 -0.22, 2.6 0.12
1 OR = Odds Ratio, CI = Confidence Interval
Characteristic log(OR)1 95% CI1 p-value
Ferritin_less30_19_21w


    ID — —
    Non-ID 0.14 -1.0, 1.3 0.8
Smoker_1st_trim 0.25 -1.0, 1.5 0.7
GestationalDiabetes 0.39 -0.19, 1.0 0.2
Preeclampsia -0.58 -2.7, 1.3 0.6
Gravidity -2.2 -4.1, -0.58 0.015
Infant_GAw -1.9 -2.5, -1.4 <0.001
Small for Gestational Age


    No — —
    Yes 6.8 5.0, 9.2 <0.001
IronSupp_PreEarlyPreg 1.1 -0.21, 2.6 0.12
1 OR = Odds Ratio, CI = Confidence Interval
Characteristic log(OR)1 95% CI1 p-value
Ferritin_less15_32_34w


    ID — —
    Non-ID 3.4 0.35, 8.5 0.087
Smoker_1st_trim 1.6 -1.0, 4.4 0.2
GestationalDiabetes 1.0 -0.16, 2.7 0.14
Preeclampsia -0.23 -7.6, 6.4 >0.9
Gravidity -4.6 -9.9, -0.92 0.039
Infant_GAw -2.6 -4.4, -1.5 <0.001
Small for Gestational Age


    No — —
    Yes 8.6 4.7, 15 0.001
IronSupp_PreEarlyPreg 0.12 -2.8, 3.3 >0.9
1 OR = Odds Ratio, CI = Confidence Interval
Characteristic log(OR)1 95% CI1 p-value
Ferritin_less30_32_34w


    ID — —
    Non-ID 2.4 -0.14, 5.5 0.074
Smoker_1st_trim 1.5 -1.3, 4.6 0.3
GestationalDiabetes 1.1 -0.01, 2.5 0.081
Preeclampsia -0.57 -9.9, 6.8 >0.9
Gravidity -3.8 -8.9, -0.54 0.054
Infant_GAw -2.6 -4.6, -1.5 <0.001
Small for Gestational Age


    No — —
    Yes 8.5 4.7, 16 0.001
IronSupp_PreEarlyPreg 0.42 -2.6, 4.0 0.8
1 OR = Odds Ratio, CI = Confidence Interval

Multivariate model results:

  • For the full sample, Ferritin status at the 33w visit was significantly associated with LBW status. Mothers that were non-ID at the 33w visit have significantly higher odds of LBW than those who were ID (both cutoffs).

  • ID status at the 15w visit was no longer significantly associated with LBW after adding in the covariates

  • No evidence of a statistical association between ID and LBW after excluding participants with Ferritin > 150 and/or CRP > 10. The 33w visit was close to significant for both ID thresholds, but ever so slightly higher than p = .05.